This research aims to learn about ultrafast processes in molecules, ions, molecular aggregates and proteins by means of subpicosecond and picosecond laser methods. The work will focus on dynamical processes which include: vibrational energy relaxation in simple systems such as aqueous ions; vibrational energy transfer and partitioning in molecular aggregates; studies of the heating of molecules by laser excitation and the subsequent cooling pathways and dynamics; more precise and shorter timescale characterization of molecular motion of both ground and excited states in model condensed phase systems and of amino acid residues in proteins; and extensive studies of heme-ligand dynamics and cooperative effects in hemoglobin and related proteins using a variety of novel spectroscopic methods. The methods include: subpicosecond transient absorption spectroscopy; ultrafast (ca. 350 fs) fluorescence decays, anisotropies and spectra of amino acids, particularly tryptophans and tyrosines; picosecond transient Raman spectroscopy; a new approach to picosecond infrared spectroscopy; and nonlinear spectroscopies such as transient gratings and polarization methods. The goal of the hemeprotein experiments is to track the structural processes induced by ligand photodissociation into regions of the protein that are appropriately distant from the heme. In particular UV absorption, polarization spectra and subpicosecond fluorescence decays will be used to explore side chain responses to photodeligation. Fundamental questions concerning the effects of molecular motion on energy transfer will be addressed. Of particular interest is the study of ultrafast motions occurring in the nearly free rotation regime. The motional studies are brought into relation with theory by means of moleculary dynamics simulations.